There are sealant-incorporated tires known from Japanese Patent Application Laid-open Nos. 4-5029 and 8-323875, in which a sealant chamber is defined inside a tread of a tire body and filled with a sealant, so that the puncture of the tread by a nail or the like is sealed by the sealant encapsulated in the sealant chamber to retard the leakage of air through the puncture.
It should be noted here that in the sealant-incorporated tire described in Japanese Patent Application Laid-open No. 4-5029, the sealant is encapsulated in the sealant chamber at a state of forming a crude tire and for this reason, there is a possibility that the sealant might be deteriorated by heat produced during vulcanization and formation of the tire, resulting in a reduced sealing effect. The sealant-incorporated tire described in Japanese Patent Application Laid-open No. 8-323875 suffers from the following problems: The sealant is charged by a syringe into the sealant chamber in the vulcanized and molded tire and hence, there is not a possibility that the sealant might be deteriorated by heat, but air remains in the sealant chamber, and it takes a long time for charging the sealant.
There are also sealant-incorporated tire tubes known from Japanese Patent Application Laid-open Nos. 58-74342 and 9-300481, in which a sealant is charged into the tire tube, so that the puncture of the tire tube by a nail or the like is sealed by the sealant to retard the leakage of air.
In the tire tube described in Japanese Patent Application Laid-open No. 58-74342, a sealant-incorporated capsule is inserted into the tire tube before being vulcanized and molded, so that the capsule is broken by an external force after vulcanization and molding of the tire tube to disperse the sealant within the tire tube. In the tire tube described in Japanese Patent Application Laid-open No. 9-300481, the sealant is charged into the sealant chamber through a sealant charging bore made in the tire tube in a state in which air has been charged into the air chamber in the tire tube to force the air out of sealant chamber.
In the former sealant charging process, however, there is a possibility that the tire tube might be damaged, when the external force is applied to break the capsule, and moreover, there is a possibility that the sealant might clog a pneumatic valve mounted in the tire tube. The latter sealant charging process suffers from a problem that it is difficult to completely discharge the air present in the sealant chamber, and also it takes a long time for discharging the air out of the sealant chamber.